Device for tensioning stitches being formed in hosiery dual-bed flat machines

ABSTRACT

In a flat bed knitting machine having spaced inclined needle beds wherein a cam carriage moves back and forth along the needle beds to reciprocate the needles to form stitches thereon, during which the needles of both beds thereof cross each other as the knitting waves of the needles move back and forth along the needle beds, the combination therewith of a pair of rod-like stitch tensioning stems supported by, and movable with, the cam carriage, each stem having a free end portion extending parallel to the direction of travel of the cam carriage with the free ends laterally positioned and extending in opposite directions, the stems being interchangeably movable into, and out of, operative positions between the needle beds wherein the operatively positioned stem is beneath the crossed needles, and is in contact with, and exerts pressure upon, the stitches on the crossed needles of the knitting waves. The machine has means to interchangeably position the stems at each end of the cam carriage stroke, so that as the cam carriage moves in each of its directions of travel, the stem having its free end extending in the opposite direction is placed into operative position.

United States Patent Giachetti et al.

[ 51 Aug. 22, 1972 [54] DEVICE FOR TENSIONING STITCHES BEING FORMED INHOSIERY DUAL- BED FLAT MACHINES [72] Inventors: Alfredo Giachetti; EnzoMaranghi; Lastra A. Signa; Angiola Pieracci, all of Staffoli, Italy [73]Assignee: G. Billi & C. S.p.A., Firenze, Italy [22] Filed: Nov. 19, 197021 Appl. No.: 91,122

[52] U.S.Cl ..66/64 [51] Int. Cl. ..D04b 7/04 [58] Field of Search ..66/147, 60, 64

[56] References Cited UNITED STATES PATENTS 3,049,900 8/1962 Bram..66/60 3,007,324 11/1961 Bram ..66/64 3,153,922 10/1964 Bram ..66/64Primary Examiner-Ronald Feldbaum AttorneyLouis Necho ABSTRACT In a flatbed knitting machine having spaced inclined needle beds wherein a camcarriage moves back and forth along the needle beds to reciprocate theneedles to form stitches thereon, during which the needles of both bedsthereof cross each other as the knitting waves of the needles move backand forth along the needle beds, the combination therewith of a pair ofrod-like stitch tensioning stems supported by,- and movable with, thecam carriage, each stem having a free end portion extending parallel tothe direction of travel of the cam carriage with the free ends laterallypositioned and extending in opposite directions, the stems beinginterchangeably movable into, and out of,

operative positions between the needle beds whereinv the operativelypositioned stem is beneath the crossed needles, and is in contact with,and exerts pressure upon, the stitches on the crossed needles of theknitting waves. The machine has means to interchangeably position thestems at each end of the cam carriage stroke, so that as the camcarriage moves in each of its directions of travel, the stem having itsfree end extending in the opposite direction is placed into operativeposition.

5 Claims, 17 Drawing Figures PATENTEDwszz m2 SHEET 1 0F 7 22 3A V 2A 97/0.

I L. w 12 3 l 9 v I N v E NTO R s ALFREDO Gincusrri, [v20 MnRANsni,ANeiow RERRCCL ATTORNEY iQ M PATENTEDwszz I912 3.685317 SHEET 2 [IF 7INVENTORS ALFREDQGimmfrri Euzo MHRHNGHI; ANG IOLO PERAccI ATTORNEYmemanwsez 1912 3.68531 7 SHEET 3 [1F 7 Fig.7A

INVENTORS ALFRmGiAcHETri, EuzoMaaqneui Ausl oLo Emacs ATTORNEY PATENTEDM1822 I97? 3; 685; 3 1 T SHEET t [If 7 Fig. 9

INVENTORS ALFREVOCIhCHETTI; EMZOMARMGHJ', AueioLo PERncci n T T o R N EY PATENTEDAum I912 3685317 SHEET 5 UF 7 INVENTORS I ALFREDO GIhcHETTIEuzo MHRRNGHI, AusiowRzRncci A-r-roRN EY 951w w mmsnmzm" 3.685317 SHEET6 OF 7 Fig. 13

I N VE N To R S ALFREDO GiAcHEn-I, Euzo MRRHNGHL Aueiow mRAcci BTIVORNEYPATENTEDAHEZZ 1912 1685317 SHEET 7 OF 7 Fig. 15

Fig.16

INVENTORS ALFREDO BiAcHETTi, Euzo MHRANQHL Ausibm PERncci ATTORNEYDEVICE FOR TENSIONING STITCHES BEING FORMED IN HOSIERY DUAL-BED FLATMACHINES The present invention relates generally to the art of knitting,and more particularly to flat independent latch needle knitting machinesof the type having opposed inclined needle beds, and to the provision insuch machines of means to exert tension directly upon the stitches onthe shanks of the needles, thereby to assist in the latch clearing andthe casting-off of the stitches from the needles.

In the type of machine above set forth, wherein the needles of each bedthereof cross each other during the knitting operation, it has been thepractice to use weights, or to use a take-up apparatus on the fabricbeing produced by the machine in order to assist in the stitch formationon the needles. It has also been the practice to use a starting comb onthe machine to assist in the formation of the first courses of fabricbeing made upon the machine.

It is the principal object of the present invention to provide means toautomatically assist in the formation of stitches in fabrics, and in thestarting courses of fabrics made upon the type of machine above setforth, without the use of weights, fabric take-up apparatus, or startingcombs.

It is also an object of the present invention to providestitch-tensioning means upon, and movable with, the reciprocating camcarriage used on the type of machine above set forth which will be indirect contact with, and will exert tension upon, the stitches on theshanks of crossed needles in the knitting waves thereof, thereby to aidin the knitting process upon the needles of the machine.

With the above and other objects of the present invention in view, aswill be readily apparent from the following detailed description of thepreferred embodiments thereof shown in the accompanying drawings, theinvention resides in the stitch-tensioning means for flat bed knittingmachines as illustrated and described, and as set forth in the appendedclaims.

In the drawings:

FIG. 1 is a schematic plan view of the two parallel needle beds of aflat knitting machine, and of the reciprocating cam carriage associatedwith the needle beds to actuate the needles, and showing a pair ofstitch-tensioning members of the present invention in place uponopposite sides of the cam carriage.

FIG. 2 is a view, similar to FIG. 1, of one end of the machine with thecam carriage at the corresponding end of the needle beds with one of thestitch-tensioning members in operative position, and with the other ofthe stitch-tensioning members out of operative position.

FIG. 3 is a view, similar to FIG. 1, of the opposite end of the machinewith the cam carriage at the corresponding end of the needle beds andwith the operative and non-operative positions of the stitch-tensioningmembers reversed.

FIG. 4 is a cross-sectional view of the machine as taken along the lineIV-lV of FIG. 1.

FIG. 5 is an enlarged detail view of a portion of FIG. 4 showing therelationship between the pair of stitchtensioning members of the presentinvention and the needle beds.

FIG. 6 is a view similar to FIG. 5, showing an intermediate position ofthe present stitch-tensioning members as they are moved into, and outof, their operative positions.

FIG. 7 is a perspective view of one of the stitch-tensioning members ofthe present invention and its suptensioning member being shown incross-section as taken along line VIII-VIII of FIG. 7.

FIG. 9 is a plan view similar to FIG. 1, showing a modified form ofmeans to place the stitch-tensioning members of the present inventioninto, and out of, their operative positions.

FIG. 10 is an enlarged view of one end of the machine of FIG. 9.

FIG. 11 is a cross-sectional view of the machine as taken along the lineXl-XI of FIG. 9.

FIG. 12 is an enlarged view, partly in section, showing the modifiedmeans to place the present stitch-tensioning members into, and out of,their operative positions.

FIG. 13 is a view similar to FIG. 12, showing an intermediate positionof the stitch-tensioning members as they are moved into, and out of,their operative positrons.

FIG. 14 is a perspective view of one of the stitch-tensioning members ofthe present invention along with its support and operating means.

FIG. 15 is a cross-sectional view of the operating means for thestitch-tensionin g members as taken along line XV-XV of FIG. 13; and

FIG. 16 is a view similar to FIG. 15, as taken along line XVIXVI of FIG.13.

The stitch-tensioning members of the present invention and a first meansof operating the same are shown in FIGS. 1 to 8 as having been appliedto an otherwise conventional two-bed flat independent latch needleknitting machine wherein the needle beds are inclined. The machineframe, indicated at 1, suitably supports a pair of spaced parallelrectangularly shaped needle beds 3 and 3B which are symmetricallyinclined relative to a vertical plane A-A midway therebetween. Theneedle beds are each provided with a series of spaced transverselyextending parallel slots 5, FIG. 5, within which latch needles 7 areadapted to reciprocate, it being understood that when the needles of thetwo needle beds are moved toward their latch clearing positions, theycross each other as shown in FIG. 8. The yarn, indicated at Y, is fed tothe needles by a yarn guide 8 which is mounted upon and moves withreciprocating cam carriage 2 of the machine. The cam carriage isprovided with a pair of oppositely positioned cam plates 9 and 9A, eachof which is provided with the necessary cams to cause the needles tomove through their normal knitting waves. The cam plate 9 is associatedwith the needles of bed 3 and the cam plate so that the latter and thecam carriage maybe moved- I back and forth along the rails and theneedle beds.

A pair of like stitch-tensioning members of the presentinvention areindicated at 10 and 12 with the former mounted upon cam plate 9A and thelatter mounted upon cam plate 9. Thev memberl and its supporting bracketis shown in FIG. 7, and it will be understood that the'descriptionthereof will also suffice for the member 12. The supportingbracketcompn'ses a block or plate 11 and a rib 13 depending therefrom.

the boss 18 of member engages cam face 22A. The

The member 10 is generally L-shaped and has its base portion suitablyformedto be slidably retained in a dovetail groove 10A, FIG. 7A, formedin and extending transversely of the plate 11 w'hereb'y'the member 10-may be moved transversely of the direction of travel of the camcarriage. The member 10 is placed in position at the right'hand side ofcam plate 9A, FIGS. 1-3, by

suitably securing rib 13 to the upper right-hand side of the cam plate.The member 10 is also provided with a freely extending stem portion 110positioned at' right angles to its base portion in the plate 11 sothatthe stem lloextends parallel to the direction of travel of the camcarriage and is disposed in the vicinity of the upper ends of the needlebeds. The member 12 is similarly mounted upon the left-hand-portion ofcam plate 9 so that its stem 112 extends toward the right in parallelopposed relation to the'stem 110 which extends toward the left, FIGS.'l-3.

The base portions of the members 10 and-l2 are provided with upstandingcylindrically shaped bosses 18 and 20, respectively. Set screws 16 arethreadedly engaged in suitable apertures formed in the bosses l8 and 20and serveto suitably tension coil-springswhich are disposed in secondand smaller apertures extending through the bosses and the baseportions. The coil springs yieldingly press balls 14 against the bottomsof the slots in the'plates 11 within which the base portions of themembers 10 and 12 are slidingly disposed. It will be noted that there isa pair of spaced depressions 14A and 148 formed in the platesll withinwhich the balls 14 may be seated when the members 10 and 12 are movedtransversely of the cam plates. Such transverse movement is imparted tothe members 10 and 12 by elongated stationary cam members 22, 24, 26,and 28, secured to the end portions of the uppermost pair of rails 3A.The cams 26 and 28 have angled faces 26A and 28A which extend towardeach other and which are positioned so as to engage the boss 2001 member12 as the cam plate 9 moves to each end of the cam face 26A acting onboss 20 moves member 12 I transversely to its non-operative position,FIG. 5, in which ball 14 is seated in depression 148, and stem 112 ismoved laterally away from vertical plane A-A. At the same time, cam face22A acting on boss 18 moves member 10 transversely to its operativeposition, FIG. 5, in which ball14 is seated in depression 14A, and stem110 is moved laterally toward, and into, the vertical plane A-A betweenthe needle beds. It will be understood that the members 10 and 12 aremaintained in their respective positions by the seated balls 14.

Conversely, when the cam carriage moves to the right, FIG. 3, the boss20 of member 12 engages cam face 28A while the'boss 18 of member 10engages cam face 24A. The cam face 24A acting on boss 18, moves member10 transversely to its non-operative position in which ball 14 is seatedin depression 148, and stem 1 l0 is'moved laterally awayfrom verticalplane A-A. At the same time, cam face 28A acting .on boss 20, movesmember 12 transversely to its operative position in which ball 14 isseated in depression 14A, and stem 1 12 is moved laterally intooperative position between the needle beds, as in FIGS. 1 and 4. In FIG.6, the members 10 and 12 are in mid-positions, with the ball 14 midwaybetween the depressions 14A and 143, as the member 12 is being moved, inthe direction of its arrow, toward operative position; and as the member10 is being moved, in the direction of its arrow, toward non-operativeposition. The arrangement is such that when the cam carriage moves tothe left, FIG. 1, the member 12 is in operative position, with member 10in non-operative position, and that when the cam carriage moves to theright, FIG. 2, the member 10 is in operative position with the member 12in non-operative position. Also, thatmembers 10 and 12 are so operatedthat when each thereof is in operative position, the free end of itsstem extends in the direction opposite to the direction of travel of thecam carriage.

The cams on the cam plates 9 and 9A actuate the needles in both beds toform knitting waves of the neemachine. Similarly, the cams 22 and 24have angled the stem 112 of member 12- isin operativeposition betweenthe needle beds, and stem 110 of member 110 is in non-operative positionlaterally of the needle beds,

the boss 20 of member 12 engages cam face 26A while I dles as the camcarriage moves back and forth across the machine, the knitting wavesmoving with the carriage. The moving knitting wave, which is caused bythe needles reciprocating between stitch-forming and latch-clearingpositions, is formed in the space between the closed end of the stem andthe closed end of the stem 112. Thus, since the needles rise after thepassage of the closed end of the stem 1 10 or of the stem 1 12,depending upon the direction of travel of the cam carriage, they areraised and cross each other in the space above the moving stems, as inFIG. 8. In doing so, the stem 110 (and 112), acts as a depressor to holddown stitches C on the shanks of needles 7 as the latter areprogressively raised and, also to hold the stitches C as yarn is drawnby the progressively descending needles to form new stitches to be drawnthrough the stitches .C. By the time the newly formed stitches aredrawn, and the needles have moved to lowered position, the free taperedend of the stem 110 (and 112), has passed by the lowered needles as theknitting wave and the cam carriage moves along the needle beds. As shownin FIG. 8, the cross-section of the stem 110 (and 112), is preferablysuch that its upper portion is provided with a pair of flat surfaceshaving the same inclination as that of the needle beds, while its lowerportion is arcuately shaped to slide along the stitches C. The stem 110(and 112), is disposed so as to be very close to the needles passingthereover, and so as to exert downward pressure or tension on thestitches C of the fabric M. to aid in the stitch formation and to act asa take-up for the fabric.

In the apparatus described, the stitch-tensioning stems 110 and 112 areadapted to be placed into, and out of, their operating positions onlywhen the cam carriage is at the ends of its stroke. Other apparatus, toplace the stitch-tensioning members into, and out of, operativepositions at any place along the needle beds at corresponding positionsof the cam carriage stroke, is shown in FIGS. 9-16. In the modificationof FIGS. 9-16, the stitch-tensioning members are given a compound motionso as to be entered between, and to be withdrawn from, the needle beds.It will be understood that the stitch-tensioning stems of the members ofFIGS. 9-16 act upon the stitches C on the needles in the same manner asthose shown in FIGS. 1-8. Inasmuch as the apparatus used upon each ofthe pair of cam plates in FIGS. 9-16 is similar, like characters havebeen used for similar parts thereof, and it will be sufficient todescribe the means used for the positioning of one, only, of thestitch-tensioning members.

In FIGS. 9-16, a two-bed flat knitting machine is shown in which theslotted needle beds thereof are indicated at 121. The upper ends of thewalls between the needle bed slots have conventional shoulders 121A,FIG. 12. The pair of cam plates of the cam carriage are indicated at123, with the carriage itself moving back and forth along rails 125located above the needle beds. The cams on the cam plates 123 actuatethe needles in the same manner as the cams on the cam'plates 9 and 9A ofFIGS. 1-8.

A bracket 127, FIG. 12, is secured to each of the cam plates 123, and ablock 129 is supported by each bracket so as to overhang theupper end ofeach cam plate 123. The arrangement is such that one block 129 is at oneend of one cam plate 123, while the other cam block 129 is at theopposite end of the other cam plate 123. Each block 129 provides ahousing for a stitchtensioning member 137 and its operating means, andto this end the block 129 is slotted as at 131, to receive the member137 between the side walls of the slot. Each member 137 is provided witha forwardly extending stem 139, similar to the stems 110, 112, of FIGS.1-8. The member 137 is provided at its tail-end with a depending slottedbracket 141, and with a depending apertured bracket 149 spaced from thebracket 141. A pin 133 extending between, and anchored in the walls ofhousing 129 passes freely through slot 143 of bracket 141. A drum 135,rotatably joumalled in the side walls of housing 129, is also slotted asat 145, to receive the member 137 and its bracket 149 therein. The sidewalls of the slot 145 have a pin 147 extending therebetween with the pin147 extending freely through the aperture in bracket 149 of the member137. The drum 135 is provided with a shaft 135A of reduced diameterextending beyond the housing 129, and upon which is fixed a gearedpinion 151. The pinion 151 meshes with, and is turned by, the teeth of arack 153A formed on a rod 153, the latter being adapted to reciprocatein a direction normal to the direction of travel of the cam carriage, asshown by the arrow f10, FIGS. 13, 14. Each rod 153 is supportinglyguided at one end thereof in a bracket 155, FIGS. 10, l l, on a camplate 123, and at the other end thereof by a pin 157 extending freelythrough a slot in the rod 153 and anchored in a flange on the bracket127.

It will be noted that lengthwise movements of the rack rod 153 willcause back-and-forth partial rotations of the drum and, accordingly,there will be backand-forth arcuate movements of the off-center pin 147.As the pin 147 is arcuately moved between its limit positions, (shown atthe left-hand and right-hand sides of FIG. 12), it accordingly movesmember 137, (and stem 139), toward, and away from, the needle beds, themember 137 at the same time being pivotally movable about, andlengthwise movable along, the pin 133. This results in arcuate movementsfor the stem 139 which permits the latter to be placed into, and out of,operative position between conventional needle beds. The operativeposition of one stem 139 is shown at the lefthand of FIG. 12, while theinoperative position of the other stem 139 is shown at the right-handside of FIG. 12. It may be noted, FIG. 13, that when the rack rods 153are at the mid-points of their strokes, the members 137 position theirstems 139 above the needle beds 121. The free and closed ends of thestems 139 have the same relation to the cam plates 123, as-the stems 110and 112 have in relation to the cam plates 9 and 9A of FIGS. 1-8.

The portion of the rack rods 153 extending through their supports 155are each provided with one or more pairs of spaced rollers 159, FIGS.10, 11, which straddle horizontally extending rails 161. The rails 161project upwardly from the faces of horizontally extending plates 163,disposed on each lateral side of the needle beds. Each plate 163 has apair of spaced offset slots 165 therein, and through which pins 167freely extend, the pins 167 extending upwardly from, and being supportedby, suitable brackets 169 affixed to the respective needle beds. Theplates 163 are thus slidingly supported on the brackets 169 and arecapable of endwise movement relative thereto within the limits of theslots 165. The shape of the slots 165 is such that endwise movement ofthe plates 163 will cause the latter to assume each of a pair oflaterally offset positions, depending upon the direction in which theplates 163 are moved. Such movement of the plates 163 between itslateral positions causes the rails 161 to move in a direction normal tothe direction of travel of the cam carriage, and this causes the rackrods 153 to reciprocate. Such movement of rack rods 153 causes thestitch-tensioning members 139 to be moved into, and out of, theiroperative positions.

The plates 163 may have appropriate endwise movement imparted to them bya pattern mechanism of any suitable type, such as indicated at 170 inFIG. 9, at one end of the machine. Each of the plates 163 is suitablyconnected at one end thereof to the pattern mechanism 170, by pull rodsor wires 171, while the other ends of the plates 163 are each suitablyconnected to one end of a tensioned spring 173, of which the other endis suitably anchored on the frame of the machine. Thus, under patterncontrol, the plates 163 may be moved back and forth between their endpositions at any time during the stroke of the cam carriage, accordinglyto move the rack rods 153 by the lateral movement of the rails 161.Consequently, the positions of the stems 139 may be reversed in anyposition of the cam carriage along the needle beds where it is desiredto reverse the movement of the cam carriage. The positions of the twoplates 163 being under pattern control, their movements are timed sothat interference between the stems 139 is avoided. If desired, themovements of plates 163 may be such as to provide for intermediateinactive positions of both stems 139, as in FIG. 13, or the movements ofthe plates 163 may be such as to provide for fully inactive positions ofboth stems 139, such as is indicated for one of the stems at theright-hand side of FIG. 12.

What we claim is:

1. In a flat knitting machine of the type having a pair of spacedinclined needle beds, said needle beds being slotted, latch needlesadapted to reciprocate in the slots of said needle beds to form stitchesthereon, a cam carriage adapted to move back and forth along saidneedles beds, said cam carriage having a pair of cam plates movabletherewith, said plates being individually associated with said pair ofneedles beds to reciprocate the needles in each of said needle beds toform knitting waves thereof during which said stitches are formed onsaid needles, said knitting waves also moving back and forth along saidneedle beds during which the hook ends of the needles in said knittingwaves cross each other, and the combination therewith of a pair ofstitchtensioning members individually mounted upon said pair of camplates and movable with said cam carriage back and forth along saidneedle beds, each of said pair of members being generally L-shaped withone arm of the L-shape providing an elongated free end portion of saidmember and with the other arm of the L-shape providing a base portion ofsaid member, said pair of members being individually mounted upon saidpair of cam plates in such manner that said free end portions thereofextend generally parallel to the direction of travel of said carriageand that said base portions thereof are movable normally to thedirection of travel of said cam carriage, said free end portions of saidmembers being laterally positioned and extending in opposite directions,said base portions of said members being so normally movable at each endof the stroke of said cam carriage thereby. to interchangeably placesaid free end portions of said members into and out of operativepositions at each end of the stroke of said cam carriage, the free endportion of the operatively placed one of said members being disposedbetween said needle beds and beneath said crossed needles in saidknitting waves in contact with the stitches on said crossed needlesthereby to exert tension thereon, the free end portion of theoperatively placed one of said members extending in the directionopposite to the direction of travel of said cam carriage.

2. In a knitting machine as in claim -1 wherein the base portions ofsaid members are each provided with a roller extending upwardlytherefrom, wherein said machine is provided with a pair of cams at eachend of said needle beds, and wherein the pair of cams at each end ofsaid needle beds is adapted to engage said rollers at each end of thestroke of said cam carriage to move the base portions of said members insaid direction t er toi terc an ea 1 la e 'd free nd 0 ions 0 sai inemrs iiito an ofsa ifi operative p bsiiions thereof.

3. In a knitting machine as in claim 1 wherein said free endportions ofsaid members follow curved paths in their movements into and out of saidoperative positions thereof, and wherein said curved paths are effectedby imparting an arcuate movement to one end of the base-portions of saidmembers while at the same time imparting a sliding and pivotal movementto the other end of said base portions.

4. A knitting machine as in claim 3 wherein a housing is provided oneach of said cam plates, wherein said housing is provided with wallsdefined by a slot therebetween, wherein a pin is supported by the wallsof said housing and extends across said slot thereof, wherein a drum isrotatably mounted in the walls of said housing and extends across saidslot thereof, wherein said drum is provided with walls defined by a slottherebetween, wherein an eccentrically positioned pin is supported bythe walls of said drum and extends across said slot thereof, wherein thebase portion of one of said members is disposed in said slots in saiddrum and in said housing, wherein said one end of the base portion ofsaid member is provided with a transversely extending aperture throughwhich said drum pin freely extends, and wherein said other end of saidbase portion is provided with a lengthwise extending slot through whichsaid housing pin freely extends.

5. A knitting machine as in claim 4 wherein a rack and pinion areoperatively related to said drum, wherein said rack is adapted to bereciprocated in the direction normal to the direction of travel of saidcam carriage to oscillate said drum, wherein a rail is provided so as toextend parallel to the direction of travel of said cam carriage, whereinsaid rack is operatively related to and moves back and forth along saidrail, and wherein said rail is laterally movable thereby to reciprocatesaid rack and to oscillate said drum.

1. In a flat knitting machine of the type having a pair of spacedinclined needle beds, said needle beds being slotted, latch needlesadapted to reciprocate in the slots of said needle beds to form stitchesthereon, a cam carriage adapted to move back and forth along saidneedles beds, said cam carriage having a pair of cam plates movabletherewith, said plates being individually associated with said pair ofneedles beds to reciprocate the needles in each of said needle beds toform knitting waves thereof during which said stitches are formed onsaid needles, said knitting waves also moving back and forth along saidneedle beds during which the hook ends of the needles in said knittingwaves cross each other, and the combination therewith of a pair ofstitch-tensioning members individually mounted upon said pair of camplates and movable with said cam carriage back and forth along saidneedle beds, each of said pair of members being generally L-shaped withone arm of the L-shape providing an elongated free end portion of saidmember and with the other arm of the L-shape providing a base portion ofsaid member, said pair of members being individually mounted upon saidpair of cam plates in such manner that said free end portions thereofextend generally parallel to the direction of travel of said carriageand that said base portions thereof are movable normally to thedirection of travel of said cam carriage, said Free end portions of saidmembers being laterally positioned and extending in opposite directions,said base portions of said members being so normally movable at each endof the stroke of said cam carriage thereby to interchangeably place saidfree end portions of said members into and out of operative positions ateach end of the stroke of said cam carriage, the free end portion of theoperatively placed one of said members being disposed between saidneedle beds and beneath said crossed needles in said knitting waves incontact with the stitches on said crossed needles thereby to exerttension thereon, the free end portion of the operatively placed one ofsaid members extending in the direction opposite to the direction oftravel of said cam carriage.
 2. In a knitting machine as in claim 1wherein the base portions of said members are each provided with aroller extending upwardly therefrom, wherein said machine is providedwith a pair of cams at each end of said needle beds, and wherein thepair of cams at each end of said needle beds is adapted to engage saidrollers at each end of the stroke of said cam carriage to move the baseportions of said members in said direction thereby to interchangeablyplace said free end portions of said members into and out of saidoperative positions thereof.
 3. In a knitting machine as in claim 1wherein said free end portions of said members follow curved paths intheir movements into and out of said operative positions thereof, andwherein said curved paths are effected by imparting an arcuate movementto one end of the base portions of said members while at the same timeimparting a sliding and pivotal movement to the other end of said baseportions.
 4. A knitting machine as in claim 3 wherein a housing isprovided on each of said cam plates, wherein said housing is providedwith walls defined by a slot therebetween, wherein a pin is supported bythe walls of said housing and extends across said slot thereof, whereina drum is rotatably mounted in the walls of said housing and extendsacross said slot thereof, wherein said drum is provided with wallsdefined by a slot therebetween, wherein an eccentrically positioned pinis supported by the walls of said drum and extends across said slotthereof, wherein the base portion of one of said members is disposed insaid slots in said drum and in said housing, wherein said one end of thebase portion of said member is provided with a transversely extendingaperture through which said drum pin freely extends, and wherein saidother end of said base portion is provided with a lengthwise extendingslot through which said housing pin freely extends.
 5. A knittingmachine as in claim 4 wherein a rack and pinion are operatively relatedto said drum, wherein said rack is adapted to be reciprocated in thedirection normal to the direction of travel of said cam carriage tooscillate said drum, wherein a rail is provided so as to extend parallelto the direction of travel of said cam carriage, wherein said rack isoperatively related to and moves back and forth along said rail, andwherein said rail is laterally movable thereby to reciprocate said rackand to oscillate said drum.